Windshield wiper actuating mechanism



April 12, 1960 w. K- STEINHAGEN ETAL 2,932,236

WINDSHIELD WIPER ACTUATING MECHANISM Filed Feb. 10, 1958 s Sheets-Sheet 1 com THEIR ATTORNEY nwilvroles WILL/AM K. JTEINHAGEN PHILIP L. FRANCIS ANDRIES c. DE WIZDE j ZNON PUP/N34! '7; 5 BY JOHN G. HART w? April 12, 1960 w. K'. STEINHAGEN ETAL 2,932,286

wmnsumw WIPER ACTUATING MECHANISM Filed Feb. 10, 1958 3 Sheets-Sheet 3 WILL/AM K. STEM/H465 PHILIP L. FRANCIS AND/H55 C. DE W/ZDE ZENON POPIALS'KI /Z I I BY JOHN HART THEIR ATTORNEY 2,932,286 WINDSHIELD WIPER ACTUATING MECHANISM AppiicationFebruary 10, 1958, Serial No.'7I4 ,'403 7 Claims. (Cl. 121-164) This invention pertains to actuating "mechanism for vehicle windshield wipers, and particularly to a wiper actuating system utilizing hydro-pneumatic wiper motors.

At the present .time some vehicles are equipped with air suspension, thus necessitating an air compressor and an accumulator. Since the air compressor is driven by the engine at all times, vehicles with air suspension have an abundant supply of compressed air which can be used for actuating mechanisms such as windshield wiper motors. The vvpresent invention relates to windshield wiper actuating mechanism wherein each wiper arm and blade is'connected' directly to a wiper motor. The wiper motors are of the hydro pneumatic type, i.e., the wiper motors are interconnected and'synchronized 'by a'hydraulic lirik while being actuated: by compressed air.

Accordingly, amongour objects are theprovision of actuating mechanismior a pair of windshield wipers including amotor 'for eachwiper and hydraulic means 'for synchronizing the operation of the motors; the further provision of damper means forahydropneumatic windshield wiper motor for deceleratingz'tlie motoradjacent the stroke ends thereof; the further provision of a.hy'dropneumatic, wipermotor including, means forparkin-g. the wiper motor with air underpre'ssureand' means for interrupting the connection between the motor and the source of compressed air when the motor is in thepark'ed position; the further provision of baII type snap acting reversing valv'emeansffor a pneumatic wiper motor; and

[the still further provision of alpneumatic wiper? motor including pressure. regulating means responsiveto the motor load formaintaining substantiallyconstant motor speed, as selected bytheoperator, irrespective ofvarying load conditions. i

The aforementioned and other objects are accomplished in the present invention by embodying. speed .control valve-and reversingvalve:.means in one. motor assembly for controlling,the -operation. .of .both. motors- Specifically,, each.motor constitutesan integral part of. the transmissionassembl-y fior, each wipenarm and blade. Thus,-

each motor includes. a cylinderihaving -a. reciprocable piston therein- The .cylinders. have cylinder bores of stepped diameter' and receive complementary ,pistons- .The larger .diameterportion ofieach cylinderborejlcon- I stitutes arr. .expan sible air. chamber,, and the smaller die cylinder boreais. filled with hyameter portion. -o ;eachdraulicfiuid. and-connected to. the-smaller diameter cylinwith a sector; gear attached to. a transmission,= or pivot,

shaft. .The pivot shaftcisTrotatably journalled in the housing; the outerend of: the.-pivotsl1aft' being adapted for ddvingconnectionwith a wiperra'rm'. Eaehrmotoris equippedz with aa hydraulic damper comprisingr a variable nited States Patent by 2,932,285 Patented Apr. 12, 1960 restriction in the hydraulic link between the two motors. The variable restriction comprises a. needle which moves into a fixed orifice and automaticallyrestricts the oil flow in the hydraulic link adjacent each stroke end of the motor. ln'this'manner, the-motor pistons are automatically decelerated adjacent the stroke ends toapproximate harmonic motion.

1 The master motor includes'a pressure regulating valve, a throttling valve for controlling speed and reversing 'valve means. Thepressure regulating valve includes a spring biased ball valve engageable with a plunger. The ball valve is biasedto the closed position by'the spring, and the plunger is carried'by a diagram which is urged in the opposite direction by a second spring. When the air pressure acting on the diaphragm "exceeds the load'of the second spring, the ball valve closes and inthismanner reduces and regulates the pressure of air supplied to the speed control valve from the accumulator. In order to control the pressure of air in response to the loading of the motor, the spring guide is formed-as a cylinder which receives a hollow 'fixed piston that is connected to the air cylinder of the motorhaving, the higher-air pressure. V

The reversing valve comprises a pair of balls, each "'ball being engageable withtwo O-n'ng type valve seats. Pressurized air is suppliedby the two inner valve seats, :and acts tomove'theballs'tothe intake position. The

valveballs are controlled by a saddle piecehaving two push *rod pins. The saddle "piece is actuated in timed rel-ation'tomovement oi the motor pistonby an overwhich imparts-snap action/to the inlet. In addition, when the speed controlling valve is moved tothe oii to. 'air pressure.

position, ,a parking port .is' connected The parking. portlis directly connected 'ftothe master motor cylinder through a piston controlled valve.

'ofi the "connection of the Wiper I compressed air'sto' as to prevent l'eakagelof compressed 'Wh-enthe motor piston arrives at the parked position, thevalveis automatically closed thereby cutting motor with the. supply of air through the wiper motors whenthey areirr theparked position. I v Furtherobjects and advantages of. thejpresent inventioniwillbeapp'arentfrom the following description, reference being bad to the accompanying drawings wherein preferred embodiments of the ,present invention are clearly shown.

Inthe drawings: Figure .1 is a schematic illustration of windshield wiper actuating mechanism constructed accordingt'o this in- "vention.

der. boreof: its companion motor. :Thehydranlicifluid I forms a closed hydraulic system.- for synchronizing; the

:motor assembly in the parked position.

1 partly in elevation,

'Figures 5 through -9 are views, partly in section. and 'par tly'in. elevation, 8-58 and 9'-'9, respectively of Figure 4."

taken. along lines '5-5', f66, 7-7,

lFigure'lO. is a longitudinallsectional'View of.the master 1 motor assembly at one of its strokeend positions.

a Figure llisalongitudihal sectional view ofthe. master vFigure :12 is a fragmentary sectionalviewftakenwalong line 12-a12"of'1?igure 7.

- line 1 3"--13.of Figure 6 Figure 13 ice-fragmentary sectional view' taken along With..particular reference to Figure. 1', the actuating mechanism of this invention comprises a master hydropneumatic motor 20 and a slave hydro-pneumatic motor 22. The master motor 20 includes a cylinder 24 having cylinder bores 26 and 28 of different diameters. Acomplementary shaped piston 30 is disposed within the cylinder, the piston being operatively connected to a wiper arm and blade assembly depicted by dotted line 32.

Similarly, the slave motor 22 includes a cylinder 34 having cylinder bores 36 and 38 of different diameters which receive a complementary shaped piston 40. The piston 40 is drivingly connected to a wiper blade and arm assembly indicated by dotted line 42.

The smaller diameter cylinder bores 28 and 38 of the master and slave motors are filled with hydraulic fluid and interconnected by a conduit 44. The larger diameter cylinder bores 26 and 36 comprise expansible air chambers, the bore 26 being connected by a passage 46 to a valve assembly 48 forming part of the master motor assembly.

The air chamber 36 of the slave motor is connected by conduit 50 to the valve assembly 48. The valve as sembly 48 is connected by a conduit 52 to an accumu- 1ator'54 which ischarged by a compressor 58 that is connected to the accumulator by a conduit 60. The accumulator may be charged to a pressure of 300 p.s.i.

As will be pointed out in greater detail hereinafter, the wiper motors 20 and 22 operate to impart asymmetrical oscillation to the wiper blade and arm assemblies 32 and 42 throughout their running strokes. During running operation of the motors, air under pressure is supplied to the cylinder bore 26 while the cylinder bore 36 is connected to atmosphere so that the piston 30 will move to the right. Movement of the piston 30 to the right will impart movement of the piston 40 to the left through the hydraulic link 44. Adjacent the end of the stroke of the piston 30 to the right, the valve mechanism 48 will be actuated to connect bore 26 to exhaust and bore 36 to pressure, so that the piston 40 will move to the right and force the piston to the left through the hydraulic link 44. When it is desired to turn off the wiper motor, the valve assembly 48 is actuated to apply pressure through a parking mechanism to the bore 26 so as to move the piston 30 beyond'its normal running stroke end limit to a parked position. The piston will be moved through the hydraulic link 28 to the left beyond its normal stroke end limit position to a parked position. In the parked position, the blade and arm assemblies 32 and 42 preferably will lieagainst the cowl of the vehicle, not shown, while during the running strokes of the wiper motor, the inboard stroke end limit is above the vehicle cowl.

With reference to Figure 2, the motor 20 is attached to a transmission assembly, comprising a housing 61' and a shaft 62 having a driving hea'd64 for attachment to a wiper arm. The valve assembly 48 is' disposed within a housing 66 attached to the motor cylinder 24. The slave motor, as shown in Figure 3, is likewise attached to a transmission assembly including a housing 67 and a shaft 68 having a driving head 70.

With reference to Figures 10 and 11, the master and slave motor assemblies are of identical construction except for the valve assembly 48 which is attached to the master motor. The piston 30 includes an enlarged" head portion 72 disposed within the larger diameter bore 26. The piston is formed with an integral rack 74 which meshes with a sector gear 76 attached by means of a key 79 to the pivot, or transmission shaft 62. The piston 30 includes a smaller diameter portion 78 having attached thereto a plastic cup seal 80 disposed within the smaller diameter bore 28. The seal 80 is formed with an integral contoured damper needle 82 which is movable into and out of a fixed orifice 84 formed in an end cap 86 for the cylinder to which the conduit 44 is connected. During movement of thepiston 30 from the position of Figure 10 to the position of Figure 11, the

" piece 124' is shown in its amazes to restrict the orifice, and thus restrict the flow of oil in the hydraulic link between the two wiper motors. In this manner the motor pistons will automatically decelerate adjacent the stroke ends so that the movement imparted to the wiper blade and arm assemblies approximates harmonic motion.

In addition, the motor piston 30 is formed with a notch 88 having a ramp 90. A reciprocable parking valve 92 is mounted within a valve housing 94 attached to the cylinder 24. The valve 92 controls the connection of a passage 96 with a passage 98. The valve 92 includes an enlarged head portion which is engageable with a valve seat 102 formed in the valve housing 94. The passages 96 and 98 are interconnected at all times by the valve 92 except when the piston 30 is moved beyond its normal running stroke end position to the parked position as shown in Figure 11. When the piston 30 is in the parked position, thestem of the valve 92 falls into the notch 88 whereupon the head 100 engages the seat 102 thereby closing the connection between the passages 96 and 98.

With reference to Figures 4 through 9, the transmission housing 61 is attached to the cylinder housing 24 by a plurality of screws, such as indicated by numeral ,63. In addition, the shaft 62 extends through a porting ,to a crank arm 106 having a pin 108 which receives 80.

end of the toggle spring 110 is connected to a pin 112 one end of an over-center toggle spring 110. The other formed on a yoke type rocker 114. The rocker 114 is mounted for pivotal movement about a pin 116, as shownin Figure 4, and includes an arm portion 118 having a notched 'end 120 which receives a lug 122 formed on a reciprocable saddle piece 124. The saddle piece is movable between two positions as determined by a detent element 126 engageable with notches 128 and 130 in the saddle piece. detent element 126 is biased into engagement with the saddle piece by a compression spring 132. The saddle upper position in Figure 4. Upon oscillation of the shaft 62 in the counterclockwise direction as viewed in Figure 4, the crank arm 106 through the pin 108 will move the lower end of the toggle spring 110 over center, that is on the other side of the line interconnecting the axis of the shaft 62 and the axis of pivot pin 116. When the toggle spring 110 is moved over center, the rocker 114 will move with a snap action toits other extreme position thereby moving the saddle piece 124 downwardly so that detent element126 engages notch 130.

.Upon reversal of motor piston movement, the shaft 62 will oscillate in the opposite direction so as to move 'the toggle spring 110 back across the center of the line connecting the axes of the shaft 62 and the pivot pin 116 so that the rocker arm 114 will move with a snap action back to the position of'Figure 4. 7 The rocker arm 114 moves with a snap action, and thus imparts snap action movement to the saddle piece 124. The

saddle'piece 124 controls reversing valve means, to be described, foryalternately connecting'airchambers 26 and 36 of the'motors to exhaust and pressure.

With particular reference to Figure 7, the saddle piece 124 has apair of pins 134 and 136 attached thereto.

and 148 connect with an air supply passage 150 in the -valve plate 104. The ball 138 controls the connection of passage 152 to exhaust through O-ring 142 or to press ure through O-ring 144. Similarly, the ball controls the connection of passage 154 to pressure or ex- As seen in Figure 5, the

control valve 156-is-of-therotary 1'50 normally acts to move the balls-I38rjnd 140 so that-'theyengage the exhaust O-rin-g seats 142 and 146. The pins 134 and 136'are aligned-with the -rings-142' and 146, and i with the saddle piece 124 in' its upper position, as shown in Figures4 and 7, the pin*1 3 6"has moved ball valve 140 mm engagement with O-rin'g 148; Accordingly, passage 152 is connectedtopressure-passage 150, the air pressure maintaining the-ball 138' in sealingengagement with -'0-ring 142. Upon movement of the saddle piece 124 dowwardly wherein detent l 26--'cngages notch 130, the pin 134 will engage ball 138 and force it into sealing engagement with O-ring .144. Downward movement of the pm 136 will"permit*the ai'runder pressure from passage 156" to -move"ball" 140 i into sealing engagement with O-ring 146. 7

Air under pressure issupplied to passage 150 from port 156 of the speed control valve "158. The speed type for throttling'the flowof air from passage- 16o--throu'gh-'port 156th the passage 150. The valve-disc is-formed with 'a cutav/ayportion-164, and when't-hevalve- 158 is in the off positionas shown in figure 12, a passage 166 is connected to the passage 160. The passage 166 connects with the passage 96 in the cylinder 24, and thus constitutes the parking'passage.

. When the rotary valve 156is rotated in the counterclockwise-direction as viewed-infigure 12, the port 167 is closed while the port 156 will be opened to the extent determined by the degree of rotation of the valve. Accordingly, air will be supplied from the passage 160 through the valve chamber to port 156 and thence to passage 150. Passage 154 connects with the air chamber 26 of the master motor. Passage 152 is connected with the conduit 50 that communicates with the air chamber 36 of the slave motor.

Air is supplied to the passage 166 from a combined pressure regulator valve and. pressure reducer valve indicated generally by the numeral 170 in Figure 6. The pressure regulator valve includes a ball 172 engageable with a seat 174 and urged into engagement with seat -moved by the motors.

174 by a spring 176. The ball 172 can be moved out of engagement with the seat 174 by a pin 178 attached to a plunger 180. The plunger 180 is attached to a diaphragm 182 which is responsive to air pressure in chamber 18d that is connected to passage 160. The diaphragm 182 is biased downwardly, as viewed in Figure 6, by a coil'spring 186 which. surrounds a hollow guide pin 188. The hollow guide pin 188 receives a fined hollow pintype piston 190 which is connected to a conduit 192. The pressure reducer valve operates to reduce accumulator pressure at 300 p.s.i. to 100 p.s.i. in chamber 184. As seen in Figure 13, the conduit 192 connects with a port 194 of a shuttle valve 196, the shuttle valve including a reciprocable element 193 movable in opposite directions, so as to connect either port 2% or port 292 with the port 194. Port 200 is connected to passage 294 and port 202 is connected to passage 2&6. Passage 204 connects with passage 152, and passage 206 is connected with passage 154. Ac-

cordingly whichever of the passages 152 or 154 is conthat the pressure of air supplied to passage 160will automatically increase upon an increase in theload being This feature of load demand pressure regulation will maintain motor speed substantially constant irrespective of varying load conditions as determined by the setting of the manual speed valve 1 will --be supplied-through the parking 1 58:. The inlet side'of the'ball valve-lfi is-c'oiinect'ed "to'a port 208 whichisconnectedto'the conduit 52.

"Operation of the windshield wiperac'tuating'mechanism of this invention is as follows. when the-manual control valve "162 is moved I inthe counterclockwise-direction "as viewed in Figure 12, *to unco'verport' 156, air is 'supplied'to the passage 1'50. Since'themotor'f-pist'on 30 is in theparked'position as-shownin Figure 11, air will be supplied through O-r ing 144 to-passag'e 152*and thence toconduit SOtoairchamb'er 36 of the slavemotor 22. Accordingly, the slave motor-piston 40 will move'to the right thereby causing movement l of the piston-30-to the left through the hydraulic link 44. -As'thepiston 3'0 approaches its left hand 'stroke endlirriit, the reversing valve'will be actuated by the-saddle piece 1 2 lso*'as-to connect passage '154to. pressure and passagel52to exhaust. Accordingly, *the piston 'will move to the right from the position shown inFigure 1 thereby causing movement-the slave piston 40" to the left through the hydraulic link-44. "The motors willcontinue to-operate =in a synchronined-manner as long as thevalv'e 152 is in the on position.

When the manual valve 158' is turned to the fofi position, the port 156 iscove'red and-the port 167 is opened, 'I- his 'will allow air under pressure to flow through passage 1'66 fOLpaSSagB 96. Accordingly, air

valve 92 to passage 98, the passa g'e 98; beihg conneetedby pont'99 to the {expansible ohamber Qti of the mast'er motor. I Therefore, 30

the piston 3'0 will -move =from the 'pojsitionof Figure 1 0 to the position of Figure '11, at which point the stem of the valve 92 will fall into the notch 88 thereby cutting off communication between passages 96 and 98 so that the piston 30 will come to rest in the position of Figure 11. Piston 40 of the slave motor will likewise be moved through the hydraulic link to the parked position beyond the running stroke end.

While the embodiments of the invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In combination, a fluid motor having a cylinder, a reciprocable piston disposed in said cylinder, reversing valve means for subjecting opposite sides of the piston to difierential pressures in alternate directions to reciprocate the same throughout a running stroke, piston operated means for actuating the reversing valve means at either end of the running stroke of said piston, a manual control valve for by-passing said reversing valve means and subjecting one side of said piston to a differential pressure in one direction to move the piston beyond its running stroke to a parked position, and a parking valve actuated by said piston for interrupting the differential pressure application to said one piston side when said ing valve means comprising a pair of balls, each ball being engageable with a pair of spaced valve seats, each. ball being pressure actuated into engagement with one of said seats,,piston operated means for alternately moving said balls into engagement with their other valve seats, and a manual control valve for by-passing said reversing valve means and subjecting one side of said piston to a pressure diiierentia'l in one direction to move the piston beyond its running-stroke to a parked position.

4. In combination, a fluid motor having a cylinder, a

reciprocable piston disposed in'said cylinder, reversing valve means for subjecting opposite sides of the piston to diflerential pressures in alternate directions to reciprocate the same throughout a running stroke, said reversing valve means comprising a pair of balls, each ball being engageable with a pair of spaced valve seats, each ball being pressure actuated into engagement with one of said valve seats, and a reciprocable saddle having a pair of pins movable through said one valve seat of each ball for moving it into engagement with the other valve seat, piston operated means for reciprocating said saddle at either end of'the running stroke of said piston, and a manual control valve for by-passing said reversing valve means and subjecting one side of said piston to a diflerential pressure in one direction to move the piston beyond its running stroke to a parked position.

5. The combination set forth in claim 4 wherein said piston operated means includes an over-center toggle spring for effecting snap action movement of said saddle. 6.,The combination set forth in claim 4 including a parking valve actuated by said piston for interrupting the diiferential pressure application to said one piston side when the piston arrives at the parked position.

7. In combination, a fluid motor having a cylinder, a reciprocable piston disposed in said cylinder, a source of fluid under pressure, reversing valve means for subjecting opposite sides of the piston to difierential pressures in alternate directions to reciprocate the same, said reversing valve means including a pressure inlet port and a pair of control ports which are alternately connectible the pressure responsive surface acting to assist said spring with the control port having the higher pressure potential whereby the pressure at said inlet port will be regulated in accordance with the load imposed upon said motor.

References Cited in the file of this patent UNITED STATES PATENTS 1,467,522 Amsler Sept. 11, 1923 1,619,474 Hubbard Mar. 1, 1927 1,953,454 Wollaeger Apr. 3, 1934 2,105,473 Dean Jan. 18, 1938 2,265,307 Orshansky Dec. 9, 1941 2,450,653 Galley et a1. Oct. 5, 1948 2,462,580 Watson Feb. 22, 1949 2,547,175 Sacchini Apr. 3, 1951 FOREIGN PATENTS 748,649 France Apr. 25, 1933 517,314 Great Britain Jan. 26, 1940 

